client: fix invalid iterator dereference in Client::trim_caps()wip-6599

trimming inode drops a reference to the inode's parent, it may cause
the inode's parent also be trimmed. If the cap iterator 'p' happens to
point to the inode's parent and the inode's parent is trimmed, the cap
iterator 'p' become invalid.

Fix the issue by delaying removing cap from the seesion cap list.
(similar to what the kclient does)

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/client/MetaSession.h b/src/client/MetaSession.h
index a6cf634c969..d9fcbb881d9 100644
--- a/src/client/MetaSession.h
+++ b/src/client/MetaSession.h
@@ -43,12 +43,14 @@ struct MetaSession {
   xlist<MetaRequest*> requests;
   xlist<MetaRequest*> unsafe_requests;
 
+  Cap *s_cap_iterator;
+
   MClientCapRelease *release;
   
   MetaSession()
     : mds_num(-1), con(NULL),
       seq(0), cap_gen(0), cap_renew_seq(0), num_caps(0),
-      state(STATE_NEW),
+      state(STATE_NEW), s_cap_iterator(NULL),
       release(NULL)
   {}
   ~MetaSession();